Pins on the PSC

rockerboy

Hi,

In the above picture, what do the pins W, R, B mean on the PSC? If I want to use a MAX232 converter instead of the above circuit, which pins of the PSC should I connect to the MAX 232?

Thanks

Post Edited (rockerboy) : 11/9/2007 12:18:03 AM GMT

JonnyMac

W = white (signal), R = red (+5 vdc), B = black (ground)

Mike Green

You are going to have some problems with the MAX232 since it's designed for a full duplex connection (one line in each direction) while the PSC is half duplex and it sends/receives in both directions using the same line. You could use a combination of both circuits with the transistors converting the half duplex connection into a full duplex connection, but the MAX232 doing the conversion to RS232 voltage levels. Because the MAX232 inverts its signals, you'll need another inverter or another pair of transistors to serve the same purpose.

rockerboy

Mike Green said...
You are going to have some problems with the MAX232 since it's designed for a full duplex connection (one line in each direction) while the PSC is half duplex and it sends/receives in both directions using the same line. You could use a combination of both circuits with the transistors converting the half duplex connection into a full duplex connection, but the MAX232 doing the conversion to RS232 voltage levels. Because the MAX232 inverts its signals, you'll need another inverter or another pair of transistors to serve the same purpose.

Thanks Mike. I'll try that out.

rockerboy

Hi Mike,

I'm trying to send some commands to the PSC through the serial port using Teraterm (including "!SC" in ASCII). I have used the above circuit diagram. So far the servos are not moving. Do you know what might be wrong? I have tried with 2400 and 9600 baud rates, but both aren't working.

Also, do we need a cross over cable?

Thanks,
rockerboy

Post Edited (rockerboy) : 11/10/2007 10:53:45 PM GMT